Arrangement for adjusting mechanically the angular setting of the blades of axial flow machines, more particularly in the case of axial blowers



1965 H. SCHILDER ETAL 3,159,532

ARRANGEMENT FOR ADJUSTING MECHANICALLY THE ANGULAR SETTING OF THE BLADES 0F AXIAL FLOW MACHINES, MORE PARTICULARLY IN THE CASE OF AXIAL BLOWERS Filed Dec. 18, 1963 2 Sheets-Sheet 1 Fig. I

F 7 i 10 I II 14 12 g 1965 H. SCHILDE R ETAL 3,169,532

ARRANGEMENT FOR ADJUSTING MECHANICALLY THE ANGULAR SETTING OF THE BLADES CIF AXIAL FLOW MACHINES, MORE PARTICULARLY IN THE CASE OF AXIAL BLQWERS Filed Dec. 18, 1963 2 Sheets-Sheet 2 my; I

i I i 28 l 22 23 0 i 29 O 7 i a %5 .ance with the difierent loads to be considered.

3,169,532 Patented Feb. 16, 19%5 United States Patent ice The rotors of axial flow machines such as axial blowers, turbines and the like, include generally blades the angular setting of which should be adjusted in accord- It is primarily desired to obtain such an adjustment while the machines are actually operative. g

A large number of arrangements for adjusting the angular setting of the blades are known in the art, but these prior arrangements show the drawback consisting in that, during the adjustment, the outer forces to be applied for eftecting the'adjustment and also the inner torques to which the blades are subjected under the action of centrifugal force, subject the main bearings carrying the rotor shaft to an extra load. Such an extra load increases the wear and reduces the life of such hearings to a substantial extent. This is particularly objectionable by reason of the fact that the main bearings form generly per se the weakest point of the machine as far as its life is concerned. In the embodiments provided hitherto, a portion of the adjusting mechanism is secured to the stationary section of the machine frame or to a pedestal, while the blades of which the angular setting is to be adjusted formspart of the rotor. Difiiculties' appear in practice for the mounting'of the connecting members in the adjusting mechanism as a consequence of the thermal expansions or of ashifting of the pedestal, which leads easily to seizing or binding elfects.

The drawbacks of the known arrangements are re-- moved according to our invention, through the fact that an adjusting mechanism is fitted directly on the rotor without rotating therewith since it is capable'of a relative rotary movement with reference to the rotor, said mechamay be provided, according to our invention, with a threaded rod carrying nuts adapted to be shifted in opposite directions, said nuts engaging in their turn, through the agency of bell cranks arranged in opposite directions with reference ,to each other, an adjusting rod operativelyconnected with the disc adjusting the angular setting of the rotor blades.

This leads therefore to applying the returning forces acting under the influence of centrifugal force on the rotor blades even in the absence of any adjusting procedure, which faces are absorbed to a very large extent by the adjusting mechanism and consequeutlyno extra axial load is applied on the main bearings of the rotor shaft.

It is'sulhcient for the balance of the inner forces, to provide an antagonistic torque of a reduced intensity on the outwardly projecting cardan shaft. If the threaded rod considered is designed so that it may ensure its own braking, it is not necessary to provide any such antagonistic torque on the outside of the apparatus when no adjustment is being operated.

During the adjusting procedure, the adjusting forces required may be given sufiiciently low values if the threaded rod is carried in ball or roller bearings whereby it acts with a very higheflicicncy.

Machines through which a fluid flow passes with a reduced output may include an adjusting mechanism operatin'g under the action of a crank-shaft or an eccentric nism being adapted to shift an adjusting disc fitted inside the rotor and the part played by which consists in align larly shifting the difierent blades. This arrangement is such that neither the outer adjusting forces required for operation nor the inner torques applied to the blades under the actionof centrifugal force," can lead to the application of an extra load on the main bearings carrying the rotor shaft.

The outer adjusting force adapted to angularly shift the blades may be applied to the adjusting mechanism through the agency of a suitable member such as a pivotal shaft or cardan shaft incorporating means for adjusting its length. The actual adjusting mechanism is fitted on the rotor without-being subjected to any tensioning stress. The outer bearing point required all prior known arrangements and of which the connection with the adjusting mechanism leads to the above-mentioned difiiculties, is thus cut out.

The rotary movement of the cardan shaft or of an outer extension of the adjusting mechanism for'controlling same is a function'of the angular shifting to be executed by the blades. The angular setting of the blades may be given out at a point outside the machine and, if desired, it may be transmitted to a remote station.

In machinesthrough which a fluid flow of a. mean or large importance passes, the angular setting mechanism carrying shaft, the adjusting disc being controlled through the agency of a connecting rod, of a bent crank or of an eccentric. crank shaft or eccentric carrying shaft with a view to ensuring the. desired adjustment is comparatively larger than that used in the adjusting mechanism of the type including bell cranks, which expenditure of force. is however of only ,a minor importance in the case of machines the output of which is low. 7 I

In the accompanying drawings, we have illustrated by v way' of example two embodiments of our invention as applied to an axial blower. In said drawings:-

FIG. 1 is a cross-section of the rotor of an axial blower showing a blade at the lower end of the drawing together 7 with an adjusting mechanism adapted to be used for .machines of a mean output or of a higher output,

FIG. 2 is a view of a blade as seen from above in as-' which are not subjected to any extra load during the ad-- justing procedure, are notillustrated. Reference numeral 3 designates the rotary rod or root shaft carrying a blade 4, said rod being fitted on abentlever 5 engaging in its turn a slider 6 guided inside a groove formed in the disc 7 adjusting the angular setting of the blade.

In PEG. 1, we have illustrated the adjusting disc 7' rotating with the interposition of a ball bearing 8 round;

the inner end of adjusting member or rod 9. Said rod 7 g is adaptedto slide axially and its shifting is transformed into an angular shifting of the blades 4 inside a wide angular area, as illustrated in FIG. 2. The adjusting rod 9 (FIG. 1) forming part of the adjusting mechanism which does not rotate, is adapted to slide inside the. hub

P9 forming part of the'stationary casing 11 of said ad- 1 justing mechanism. The hub 10 and the casing 11 carry? ing the rotor 1 through the agency of the ball bearing 12. T he outer end of adjusting rod '9 terminates in a head 13 engaged by the bell cranks 14 which, in their turn,

The force applied to the outer end of the 1 (FIGS. 1 and 3 is rigidly greases are adapted to rock around the pivots 15 inside the casing 11, said bell cranks 14 carrying at their ends nuts 16 screwed over the threaded rod 17. Said threaded rod is operatively connected with the cardan shaft 18 surrounded by a protecting casing 19 and incorporating means which are not illustrated for the adjustment of its length. The threaded rod 17 is provided with threads of opposite pitches engaging the two nuts and said threaded rod extends freely through a slot 20 across the adjusting rod 9.

During the angular adjustment of the blade 4, the outer torque is applied to the cardan shaft 18 and produces through the agency of the threaded rod 17, of the nuts 16 and of the bell cranks 14 an axial force acting on the adjusting rod 9 with a reaction on the pivots 15. The axial-force is transmitted by the ball bearing 8 and the adjusting disc 7 to the casing 1 of the rotor to which the reaction of the pivots 15 is also transmitted through the agency of the casing 11, the hub rigid with said casing and the ball bearing 12. The flux of energy is thus closed and the main bearings for the shaft 2 of the rotor can thus be subjected to no extra load during the adjustment.

Turning to the embodiment illustrated in FIG. 3, the ball bearing 8 is fitted over the adjusting member or sleeve 21 carrying a transverse pin 22 which is engaged by a connecting rod 23 connected in turn with the crank shaft 24-25. The latter may be replaced by an eccentric associated with rods or cams. The crankshaft or eccentric-carrying shaft is fitted inside a casing 26 which is connected through the hub 27 with the ball bearing 28 revolvably carrying the rotor 1. An outer adjusting lever 29 is fitted on an extension of the crankshaft or of the eccentric carrying shaft and projecting beyond the casing of the axial new machine. Said extension may also be replaced by a pivotal shaft of an adjustable length.

The angular setting of said extension defines that of the blades at any given moment and may be transmitted to a remote station.

The diagram and distribution of the forces appearing in the 'case of FIG. 3 correspond in principle to those described with reference to FIG. 1. No extra load is applied to the bearings of the rotor shaft 2 under the action of the adjusting forces or of the torques acting on the blades.

What we claim is:-

1. In an axial flow machine, chiefly an axial flow blower, including a rotor the blades of which are adapted to be angularly shifted round their axes, the provision of a stationary casing on which the rotor is revolvably secured, an adjusting mechanism carried inside the casing and including a pusher-member adapted to be shifted along the axis of the rotor, said pusher member including inner and outer ends, said outer end being supported by the casing means controlling said mechanism from the outside to adjust'the longitudinal position of said pusher-member inside the casing, a member coaxial with the rotor, journalled for rotation in unison therewith on the inner end of said pusher member, and adapted to be shifted in parallelism with the axis of said rotor by axial movement of said pushermember and means whereby the shifting of said mem-' ber coaxial with the rotor adjusts the angular setting of the blades.

2. In an axial flow machine, chiefly an axial "flow blower, including a rotor the blades of which are adapted to be angularly shifted round their axes, the provision of a stationary casing on which the rotor is revolvably secured, an adjusting mechanism carried inside the casing and including a threaded spindle'provided with sections of opposite pitches, nuts adapted to be. shifted in opposite directions over said sections of opposite pitches, a pusher-member adapted to be shifted along the axis of the rotor, saidpusher member including inner and to the casing, controlled by the position of the nuts on the threaded spindle and adapted to shift axially the outer end of the pusher-member, external means controlling the angular setting of the threaded spindle, a member coaxial with the rotor, journalled for rotation in unison therewith on the inner end of said pusher member, and adapted to be shifted in parallelism with the axis of said rotor by axial movement of said pushermember and means whereby the shifting of said member coaxial with the rotor adjusts the angular setting of the blades.

3. In an axial flow machine, chiefly an axial flow blower, including a rotor the blades of which are adapted to be angularly shifted round their axes, the provision of a stationary casing on which the rotor is revolvably secured, an adjusting mechanism carried inside the casing and including a threaded spindle provided with sections of opposite pitches, nuts adapted to be shifted in opposite directions over said sections of opposite pitches, a pusher-member adapted to be shifted along the axis of the rotor, said pusher member including inner and outer ends, said outer end being supported by the easing and said pusher member having an elongated slot therein intermediate its ends and through which said threaded spindle extends bell cranks pivotally secured to the casing, controlled by the position of the nuts on the threaded spindle and adapted to shift axially the outer endof the pusher-member and a cardan shaft controlling the angular setting of said threaded spindle, a member coaxial with the rotor, journalled for rotation in unison therewith on the inner end of said pusher member, and adapted to be shifted in parallelism with the axis of said rotor by axial movement of said pushermember and means whereby the shifting of said member coaxial with .the rotor adjusts the angular setting of the blades.

4. In an axial flow machine, chiefly an axial flow blower, including a rotor the blades of which are adapted to be angularly shifted round their axes, the provision of a stationary casing on which the rotor is revolvably secured, an adjusting mechanism carried inside the casing and including a threaded spindle provided with sections of opposite pitches, nuts adapted to be shifted in opposite directions over said sections of opposite pitches,

a pusher-member adapted to be shifted along the axis of the rotor, said pusher member including inner and outer ends, said outer end being supported by the casing and said pusher member having an elongated slot therein intermediate its ends and through which said threaded spindle extends bell cranks pivotally secured to the casing, controlled by the position of the nuts onthe threaded spindle and adapted to shift axially the outer end of the, pusher-member and a cardan shaft controlling the angular setting of said threaded spindle, roller-bearings carrying said threaded rod, a member coaxial with the rotor, journalled for rotation in unison therewith on the inner end of said pusher member, and adapted to be shifted in parallelism with the axis of said rotor by .axial movement of said pusher-member and means whereby the shifting of said member coaxial with the rotor adjusts the angular setting of the blades.

5. In an axial flow machine, particularly an axial flow blower, including a rotor, blade means carried by the rotor and including root shafts adapted to be angularly shifted about their axes, a stationary casing, one end of said rotor having an opening therein coaxial with its axis, a hub extending from said casing and disposed Within said opening, bearing means interposed between said hub and the rotor within the opening for journalling one end of the rotoron the hub, an axially shiftable member including a portion slidably guided within the hub and an inner end, bearing means carried by said inner end, an adjusting disc journalled on said end, means cooperatively related between said disc and said root shafts whereby axial shifting of said axially shiftable member adjusts the angular setting of the blade means and means supported at least in part W1" n said casing and operably connected to said axially shiftable member for shifting the same.

6. In an axial flow machine as claimed in claim 5 and said axially shiftaole member comprising a rod including a portion disposed Within said casing, an elongated slot through said portion, a threaded spindle disposed Within said slot and having portions of opposite pitches, nuts carried by said portion and adapted to move in opposite directions in response to rotation of said spindle, bell crank means pivotally mounted Within the casing and including opposite ends respectively connected to a nut and said rod and means for turning said spindle to shift said rod via said bell crank connection.-

7. In an axial flow machine as claimed in claim 5 and said axially shiltahle member comprising a sleeve having a portion slidably guided within said hub, a con- 6 nesting rod pivotally connected at one end within-said sleeve and having another end within the casing, a lever arm pivotally mounted within the casing and means connecting said lever arm with the other end of said connecting arm for shifting the sleeve.

References Cited by the Examiner UNITED STATES PATENTS 4,441 4/46 Woodcroft 17016G.47 X

(1846) 2,182,705 12/39 Rissone 74-4248 X 2,344,594 3/44 Bryant 74 424.8 X 2,844,404 7/58 Kristians n 17016G.47 X

FOREIGN PATENTS 382,091 11/07 France. 494,868 6/ 19 France. 1,013,765 5/52 France.

674,78 1/38 Germany.

lULlUS E. W'EST, Primary Examiner. 

1. IN AN AXIAL FLOW MACHINE, CHIEFLY AN AXIAL FLOW BLOWER, INCLUDING A ROTOR THE BLADES OF WHICH ARE ADAPTED TO ANGULARLY SHIFTED ROUND THEIR AXES, THE PROVISION OF A STATIONARY CASING ON WHICH THE ROTOR IS REVOLVABLY SECURED, AN ADJUSTING MECHANISM CARRIED INSIDE THE CASING AND INCLUDING A PUSHER-MEMBER ADAPTED TO BE SHIFTED ALONG THE AXIS OF THE ROTOR, SAID PUSHER MEMBER INCLUDING INNER AND OUTER ENDS, SAID OUTER END BEING SUPPORTED BY THE CASING MEANS CONTROLLING SAID MECHANISM FROM THE OUTSIDE TO ADJUST THE LONGITUDINAL POSITION OF SAID PUSHER-MEMBER INSIDE THE CASING, A MEMBER COAXIAL WITH THE ROTOR, JOURNALLED FOR ROTATION IN UNISON THEREWITH ON THE INNER END OF SAID PUSHER MEMBER, AND ADAPTED TO BE SHIFTED IN PARALLELISM WITH THE AXIS OF SAID ROTOR BY AXIAL MOVEMENT OF SAID PUSHERMEMBER AND MEANS WHEREBY THE SHIFTING OF SAID MEMBER COAXIAL WITH THE ROTOR ADJUSTS THE ANGULAR SETTING OF THE BLADES. 